Drought Ebbs in 2013, But Itâ€™s Not Over Yet - UNL CropWatch, Dec. 12, 2013
Figure 1. A comparison of Nebraska drought areas in 2013 (left) and 2012 shows the significant improvement in conditions, even though almost half the state is still in drought. (Source: The National Drought Mitigation Center)
Dec. 13, 2013
Drought in 2013 was nothing like drought in 2012, but it is an ongoing issue in parts of Nebraska and the United States, say experts at the National Drought Mitigation Center, based at the University of Nebraska-Lincoln.
In Nebraska, “We saw that very intense drought from 2012 drop off and improve in 2013,” said Brian Fuchs, NDMC climatologist and U.S. Drought Monitor author. “In 2012 we had a very warm, early greenup in spring that started affecting soil moisture and water availability right away. In contrast, in 2013, we had snow and very wet conditions right into the first part of May. It was very different.”
Figure 2. The U.S. Drought Monitor map for Dec. 10, 2013, showed 30% of the contiguous 48 states and 25% of all 50 states and Puerto Rico in moderate drought or worse, which is about half the drought coverage this time last year. The U.S. Drought Monitor map is produced each week by the National Drought Mitigation Center at the University of Nebraska-Lincoln, the U.S. Department of Agriculture, and the National Oceanic and Atmospheric Administration. (View larger version.)
Just under half of Nebraska was still in moderate drought or worse as of mid-December 2013 (Figure 1), which is a vast improvement from this time last year, when the state was at the epicenter of the widespread, intense drought of 2012, and 100% of Nebraska was in drought, with more than three-quarters of the state in exceptional drought.
Southwest Nebraska is the one area in the state where drought is still almost as bad as it was in 2012. “In the Panhandle and eastern third of the state, the rain came before the soils froze up,” said Mark Svoboda, leader of the Monitoring program area at the drought center. “We’ve had from 150% to 200% of normal or more since October 1. But for the southwest part of the state, there was virtually nothing.”
“The floods in Colorado brought a lot of good to our state,” Fuchs said. “They not only replenished the basin, which was dry, but also scoured the basin, getting rid of overgrown vegetation. We’re still seeing good flows in the Platte Basin and in the alluvial plain throughout the state, which soaks in and replenishes groundwater.”
He said reservoirs upstream in Colorado and Wyoming “are in much better shape than they were a year ago, so we can anticipate more water being released if we have normal to above-normal snowpack, and so far the season is looking good. Soil moisture has been replenished, too, which adds to the potential for good runoff. It’s looking like 2014 could be a much better year as far as the water that comes into the state, and water that we can hold back in Lake McConaughy.
Climatologists say that “Is the drought over?” is a notoriously difficult question to answer. One heavy rain doesn’t necessarily end a drought, especially if it runs off hard soil or falls outside a basin that fills a reservoir. And drought that is shown on the U.S. Drought Monitor map isn’t a single event. Sometimes drought areas merge over time to form one large drought, or one large drought splits into smaller dry areas. And even though rains may return to an area and replenish soil moisture for agriculture, water supply that comes from reservoirs, aquifers and other components of hydrological systems may take years to recover, or may depend on precipitation in remote mountain areas.
Figure 3. This chart shows U.S. Drought Monitor values from 2000 through the present. Drought expanded rapidly in 2012 and has been gradually declining since then. (View larger version.)
As of Dec. 10, the U.S. Drought Monitor showed 30.28% of the contiguous U.S. in moderate drought or worse (Figure 2), which is half of what it was a year ago, and slightly below the average drought coverage of 32% shown on the U.S. Drought Monitor since 2000, when the record of associated statistics began. (Figure 3 illustrates the ups and downs of drought in the U.S. since 2000.) The climatologists emphasized that 13 years is not a long basis for comparison. More significantly, average drought coverage for the Palmer Drought Severity Index, which goes back to 1895, is about 15%, according to NDMC climatologists, and it was near 13% for October, according to the National Climatic Data Center’s most recent National Drought Overview report.
The Palmer Index is primarily geared for agricultural areas and is less reliable for snowy mountainous terrain and arid regions, Svoboda said. It is one of many indicators that are incorporated into the U.S. Drought Monitor.
Figure 4. Difference between the Dec. 10, 2013 and the Dec. 11, 2012 U.S. Drought Monitor map. Greens show areas of improvement and browns show areas of worsening drought. U.S. Drought Monitor change maps are a new product from the National Drought Mitigation Center at the University of Nebraska-Lincoln. (View larger version.)
Although total drought coverage is dramatically less than it was a year ago (Figure 4), Svoboda pointed to several parts of the country where drought is either emerging or ongoing.
“This is a critical water year for the West,” he said. “Water managers in California are keeping a close eye on what happens this winter with snowpack in the Sierra Nevada range in northern California and in the Colorado River Basin.”
“The key in the West will be what happens in the water year that started in October 2013,” Fuchs said. “So far there has not been a tremendous amount of early season snows or precipitation in those areas. What we’re really hoping to see is a good snow season for them. The stress on reservoirs and water systems in the West is really going to show through if we don’t have a good winter this year.”
Hawaii has been in various degrees of drought since mid-2008, which has affected water supplies and agriculture, including livestock production. Fuchs said that drought is currently affecting 52.14% of the state, after a November peak of 67.74% and the 2013 low in June of 32.68%.
Another drought area includes parts of Nebraska, Colorado, Kansas, Oklahoma, Texas, and New Mexico, where many areas are in their third year of intense drought. “We’re definitely still talking about a long-term, multi-year drought,” Fuchs said. While those areas have seen some relief, good rains in eastern Texas, and a long, active monsoon season in New Mexico, he said, “We are still talking about the longer-term issues with drought. Surface waters, reservoirs, and ground water are still recovering. It’s going to take some time. Each water system will have to analyze what they’re going to do.”
In New England, moderate drought emerged after a dry fall, although Fuchs predicted that drought there would be short-lived: “We don’t generally see a lot of long-term issues in the Northeast.”
Communications Specialist, National Drought Mitigation Center